Steel Service Centre, Sheet Metal Distributor, Wholesale Steel, Coil Slitting, Cut-to-Length & Profile Roll-Forming HVAC Duct Guide

1. Why steel service centre HVAC is its own engineering discipline

An Australian steel service centre is a high-throughput, mixed-metal, mixed-process factory environment that combines coil-handling logistics with chemically demanding cutting, slitting and forming operations. Every distributor under the steel service centre umbrella — from a flat-product BlueScope Distribution centre at Western Port VIC processing Truecore, Colorbond, Galvalume and Zincalume coil; through an InfraBuild Sydney depot slitting and CTL-cutting reinforcing bar, merchant bar and structural plate; through an Atlas Steels Carlton VIC stainless and special-alloy service centre handling 304, 316, 316L, duplex 2205, Inconel 625, Hastelloy C-276 and titanium; to a Capral Aluminium Penrith NSW distribution facility handling 5052, 5083, 5086, 6061 and 6082 plate, sheet, extrusion and architectural section — produces its own characteristic exhaust chemistry, dust loading and capture geometry. HVAC ductwork inside a steel service centre is not a commodity. It is a process-engineering problem that touches occupational health, dust explosion safety under NFPA 484, fluid-mist management, abrasion-resistance material selection, fire-rated construction near LPG-forklift Zone 2 areas, and AS/NZS 60079 hazardous-area electrical compliance all inside the same building.

This guide writes against the full breadth of the Australian steel service centre and metals distribution sector. The flat-product distribution segment is the largest by floor area, driven by BlueScope Distribution (Western Port VIC + Port Kembla NSW — BlueScope’s own coated-steel distribution arm for Truecore structural framing, Colorbond pre-painted roofing and walling, Galvalume aluminium-zinc coated steel, Zincalume zinc-aluminium coated steel and bare hot-dip galvanised coil), InfraBuild Wire and Distribution (formerly OneSteel Distribution, now under GFG Alliance Liberty Steel ownership with the Sanjeev Gupta group, Sydney HQ, Whyalla SA EAF rebar and rod, Sydney + Melbourne + Brisbane + Newcastle reinforcing + merchant bar + structural — Australia’s biggest steel distributor by tonnage), Lysaght (BlueScope subsidiary running pre-engineered roofing, walling and structural-section roll-forming from Coomera + Sydney + Melbourne + Brisbane + Perth + Adelaide + Darwin), Stramit (CSR ASX:CSR-owned, roll-formed roofing and walling), and the broader independent service-centre network including Apex Steel, Apex Engineered Solutions, NPS Stores (Sydney + Melbourne + Brisbane + Adelaide + Perth national stockist), Coil Steels NSW, Northern Iron and Brass Brisbane, Eastern Steel, Welcome Steel, Pacific Steel, Atlantic Steel, Continental Steel, Champion Steel, Global Steel and Sheet Metal Suppliers.

The stainless steel distribution segment is dominated by Atlas Steels (Carlton VIC — biggest stainless and special-alloy distributor in Australia, handling 304, 316, 316L, 440, 13Cr martensitic, duplex 2205, duplex 2304, 317L, 904L, Inconel 625, Inconel 718, Hastelloy C-276, Monel, Nitronic 50, Nitronic 60, titanium and full super-alloy ranges), Australian Stainless Service Centre ASSC (Sydney + Melbourne + Brisbane + Perth distribution of 304, 316, 316L, 409, 430 commodity stainless) and Suntech Steel Service Centre (304, 316, duplex). The aluminium distribution segment is dominated by Capral Aluminium (ASX:CAA — Penrith NSW + Bremer Park QLD + Smithfield SA + Welshpool WA + Crestmead + Bayswater + Sumner + Wollongong — Australia’s biggest aluminium distributor, handling billet, plate, sheet, extrusion, architectural section, structural section and marine alloys 5083, 5086 and 5052, plus structural 6061 and 6082), with secondary distribution at Aluminium Specialties, Architectural Window Systems AWS and Bonded Composites Industries BCI.

The tubular steel segment runs through Orrcon Steel (BlueScope subsidiary — RHS rectangular hollow section, SHS square hollow section, CHS circular hollow section, structural and precision tube), Austube Mills (BlueScope and Manyalo merged operation, Sunshine VIC + Newcastle NSW + Welshpool WA — RHS, SHS, precision tubing), and Atlas Steels stainless tube. The structural plate segment runs through Bisalloy Steels (ASX:BIS, Unanderra NSW — quenched-and-tempered armour, wear-resistant and structural plate). Upstream reroller, galvaniser and coater operations are concentrated at BlueScope Steel (ASX:BSL, Port Kembla NSW — the country’s integrated steel mill, pickling line, CGL5 + CGL6 + CGL7 continuous galvanising lines), InfraBuild (Sydney + Melbourne + Brisbane + Newcastle reinforcing and merchant bar reroller), Liberty Steel (ASX:LIO, Whyalla SA — EAF rebar and rod) and GFG Alliance Liberty (Sanjeev Gupta-controlled). The wire and mesh segment is concentrated at InfraBuild Wire (Newcastle + Geelong — wire rod, mesh, barbed wire, chain link), Riverina Wire Industries and Newland Steel Australia. The primary aluminium smelting tier is Tomago Aluminium at Newcastle.

Across this entire sector, steel service centre ductwork must survive five demands simultaneously: cutting-fume chemistry (laser and plasma NO2, O3, Cr VI, Fe2O3, AlOH3, ZnO from coated-steel cutting), coolant aerosol management (water-based emulsion + oil mist at 5 mg/m3 STEL), abrasive swarf transport (slitter ribbons, CTL shear-drop, plasma kerf slag, abrasive water-jet garnet), combustible-metal dust risk (NFPA 484 fine aluminium below 75 micron, finer titanium and magnesium where present), and respiratory-fume control (Cr VI, Ni, Mn, Cu, Pb in legacy alloys). Each is manageable in isolation. Together they explain why a generic commercial fabricator treating a steel service centre as just another industrial job misses on the first project and walks away from the second.

This guide walks every major service centre process and explains what changes about the ductwork. We start with the regulatory backbone, then map the service centre floor section by section, then close with the SBKJ machine configuration that gives a fabricator the production envelope to serve this market from Box Hill North VIC across the country.

2. The Australian regulatory stack — AS 1668.2, AS 4254, AS 1397, AS 1163, AS/NZS 60079, NFPA 484, NFPA 660, NFPA 86

Steel service centre HVAC in Australia sits at the intersection of more than fifteen overlapping standards and codes covering building ventilation, sheet-metal duct construction, hazardous-area zoning, combustible-dust management, structural metal grades, welding fume control, oven and furnace exhaust, and workplace exposure standards. The standards stack splits into building-code compliance, occupational-health exposure compliance, hazardous-area electrical compliance, dust-explosion compliance, and process-specific metallurgy compliance.

2.1 AS 1668.2 — mechanical ventilation for buildings

AS 1668.2 is the umbrella mechanical-ventilation standard. Steel service centres typically fall under NCC Class 8 industrial occupancy (with the warehouse and racking zone often classified as Class 7b storage). Table 4 of AS 1668.2 sets minimum extract rates for metal cutting, welding, grinding, painting and storage. In practice a service centre seldom gets close to the minimum — LEV at each cutting bed, slitter line, CTL station and welding bay drives total exhaust well above the building-volume figure. Where AS 1668.2 matters most is the make-up air requirement: every cubic metre extracted must be replaced by tempered, filtered, controlled-velocity supply air, keeping the cutting and slitting floor at neutral pressure relative to office and quality-control zones, and preventing cross-contamination of paint-coated coil with adjacent welding fume.

2.2 AS 4254 — sheet metal duct construction

AS/NZS 4254.1 (sheet metal) and AS/NZS 4254.2 (flexible) govern duct construction across the normal pressure ranges — low pressure (up to 500 Pa), medium pressure (up to 1000 Pa) and high pressure (up to 2500 Pa). Most steel service centre HVAC sits inside AS 4254 ranges, but high-velocity dust mains carrying slitter swarf at 22 m/s and the inlet of pulse-jet baghouses for fine cutting fume run at vacuum loadings approaching the upper end of AS 4254 medium-pressure ratings. Reinforced spiral or heavy-gauge welded construction is the typical solution above 2 kPa vacuum.

2.3 AS 1397 — metallic-coated steel sheet, AS 1450 cold-rolled, AS 1444 grade

AS 1397 governs zinc-coated, zinc-aluminium-coated and aluminium-zinc-coated structural steel sheet — the material standard for Z275 hot-dip galvanised duct (zinc coating 275 g/m2 total both sides), G300 grade structural galvanised, Truecore Activate structural framing steel (BlueScope), Colorbond pre-painted Colorbond Steel, Galvalume aluminium-zinc 55%Al-43.4%Zn-1.6%Si, and Zincalume zinc-aluminium 55%Al-43.5%Zn-1.5%Si. AS 1450 covers cold-rolled carbon-steel sheet. AS 1444 covers steel grade for general engineering. These standards drive the input-material specification for coil decoiled at every Australian service centre — a Z275 ducting application demands AS 1397 Z275 mill certificate at coil receipt, with the zinc coating retained through the slitting, levelling and CTL process before downstream paint or end-use.

2.4 AS 1163 — structural steel tube, AS/NZS 3678+3679 — structural plate and section

AS 1163 governs structural steel hollow sections — RHS rectangular, SHS square, CHS circular — the material standard for Orrcon Steel and Austube Mills output. AS/NZS 3678 governs hot-rolled structural plate. AS/NZS 3679 governs hot-rolled structural section (universal beams, columns, channels, angles). Steel service centres distributing structural sections to fabricators reference these standards at coil receipt and at sale-to-customer documentation. Bisalloy Steels at Unanderra NSW additionally supplies quenched-and-tempered armour and wear-resistant plate to specialty specifications (Bisalloy 80, Bisalloy 320, Bisalloy 360, Bisalloy 400, Bisalloy 450, Bisalloy 500, Hardox-equivalent grades).

2.5 AS 1554, AS/NZS 1554.1, AS/NZS 1554.6 — welding standards

AS/NZS 1554.1 governs welding of structural steel; AS/NZS 1554.6 governs welding of stainless steel. Both apply to service-centre welding bays where pre-fabrication assembly of stockholding racks, cut-and-weld fabricated items, customer-cut-and-weld services and in-house ductwork are performed. AS 1665 governs welding of aluminium. AS/NZS 4453 governs welding-fume capture and control — mandating on-tool extraction (welding-gun fume extraction) plus local exhaust at every welding bay. Welding fume chemistry at service centres includes Mn (0.2 mg/m3) and Fe2O3 (5 mg/m3) on carbon-steel welding, Cr VI (0.05 mg/m3) plus Ni inhalable (1 mg/m3) on stainless welding, AlOH3 (1 mg/m3) on aluminium welding, and Cu fume (0.2 mg/m3) plus Pb (0.05 mg/m3) where copper-bronze or leaded brass is welded.

2.6 AS 3957 — dust hazard areas, the critical service centre standard

AS 3957 is the Australian dust-hazard standard and the most directly applicable single document for service centre duct designers. It covers combustible dust deflagration risk — fine aluminium below 75 micron from slitting and cutting (Class ST3 Kst 400 to 600 bar metre/sec), fine titanium and magnesium where present, abrasive blast dust (steel grit, iron shot, aluminium oxide, garnet, glass bead), and metal swarf accumulating in extract systems. AS 3957 mandates hazard-area zoning (Zone 20 for continuous explosible-dust concentration, Zone 21 for occasional, Zone 22 for unlikely), and drives the AS/NZS 60079.10.2 electrical-equipment selection downstream. For a service centre duct designer, AS 3957 forces the question at every dust collection point: what is the explosibility of the dust, what is the minimum ignition energy, what is the deflagration index Kst, and what is the engineered deflagration-protection chain (vent panels, isolation valves, chemical suppression, isolation flap valves) between the baghouse and the inbound duct? The answer drives baghouse selection, isolation-valve placement and the bonding-and-grounding of every metre of duct in the dust-laden circuit.

2.7 AS/NZS 60079 — explosive atmospheres

AS/NZS 60079 is the hazardous-area-classification standard. Steel service centres trigger AS/NZS 60079.10.2 dust classification anywhere combustible-metal dust accumulates (Zone 20/21/22 around aluminium slitting, aluminium cutting, abrasive-blast cabinets, baghouse vicinity), and trigger AS/NZS 60079.10.1 gas classification anywhere combustible gas is present (Zone 1/2). Two specific service centre locations almost always become Zone 2: the LPG-forklift charging area (propane LPG at 1.7% LEL with potential for accumulation in low-ventilation corners), and any oxy-fuel cutting station (acetylene at 2.5% LEL). Hazardous-area zoning drives Ex-rated electrical equipment requirements for fans, motors, instrumentation and duct-mounted sensors throughout the affected zones. The forklift fleet itself sits inside the Zone 2 envelope at the LPG bottle exchange area — typical service-centre design includes a dedicated outdoor or roller-shutter-isolated forklift charging area separated from the cutting and slitting hall.

2.8 NFPA 484 — combustible metals, NFPA 660 consolidation

NFPA 484 is the US National Fire Protection Association standard for combustible metals, referenced extensively by Australian steel service centre insurance underwriters and used as the de-facto engineering reference where AS standards are silent. NFPA 484 mandates wet-collection extraction for fine aluminium, magnesium and titanium dust, prohibits dry baghouses without engineered deflagration venting, and sets bonding, grounding and isolation-damper requirements that prevent a baghouse fire from propagating back into the ductwork main. Aluminium dust below 75 micron is the dominant NFPA 484 hazard at any service centre handling aluminium slitting, aluminium plate sawing, aluminium plasma or laser cutting, aluminium grinding or aluminium abrasive blasting. NFPA 660 is the 2025 consolidation standard merging the previous NFPA 61, 484, 654 and 664 dust standards into a single document. The consolidation applies the same engineering principles across dust types but with updated combustible-dust analysis requirements at facility level. Australian service centres adopting NFPA 660 in 2026 face revised dust-hazard analysis documentation, updated bonding-and-grounding requirements, and tightened isolation-valve specifications between baghouse and inbound duct.

2.9 NFPA 86 — industrial ovens for paint cure and annealing

NFPA 86 covers industrial ovens at 200 to 1000 degC. At service centres NFPA 86 applies to pre-paint and powder-coat cure ovens running 180 to 250 degC for 15 to 25 minutes, annealing furnaces (where in-line continuous annealing or strand annealing is integrated), galvanise kettle exhaust at upstream BlueScope CGL lines running 450 degC molten-zinc bath, and any hot-dip operation. Exhaust topology under NFPA 86 includes LEL monitoring at every gas-fired burner, purge cycles before lighting, explosion venting on the oven shell, dedicated exhaust risers separate from general service-centre exhaust, and burner-management systems with redundant flame supervision. Powder-coat cure ovens at Lysaght Coomera, Stramit and post-form integrated lines drive NFPA 86 compliance documentation alongside AS 4254 duct construction.

2.10 NFPA 13, NFPA 70 NEC, AS 1851, AS 1530.4, AS 1668.1

NFPA 13 governs sprinkler protection of buildings and is referenced for service-centre building protection wherever the building structure could ignite (timber roofs, mezzanine offices, paint-storage and packaging areas) or wherever combustible-coil rolls present a Class IV-equivalent commodity hazard. NFPA 70 (National Electrical Code) is referenced for hazardous-area electrical practice alongside AS/NZS 60079. AS 1851 covers the routine service and maintenance of fire-protection equipment including fire dampers, smoke dampers and the ductwork that carries them. AS 1530.4 covers fire-resistance testing of building elements including fire-rated ductwork penetrations — a 250 degC/2 hour fire-rated kitchen-exhaust style construction is sometimes called up at galvanise kettle exhaust or pre-paint cure exhaust where the duct passes through fire-rated walls. AS 1668.1 covers fire and smoke management in mechanically ventilated buildings, with fire dampers at zone boundaries and smoke-control dampers where production zones connect to office or evacuation routes.

2.11 AS 4036 boiler, AS 1318 industrial chimney, AS 4801 OHS, AS 1657 platforms

AS 4036 governs boilers used for steam generation in service-centre support utilities (parts washer, pre-treat tank heating, water-soluble coolant tank heating). AS 1318 governs industrial chimneys including service-centre exhaust stacks above the building roofline. AS 4801 (Australian standard for occupational health and safety management systems, often integrated with ISO 45001) sets the systemic OHS management framework that service centre HVAC documentation feeds into — LEV maintenance records, air-monitoring data, respiratory protection programs, hearing conservation, and dust-explosion risk assessment. AS 1657 covers fixed platforms, walkways, stairways and ladders — relevant for the elevated maintenance access to baghouse, scrubber and stack-top sampling stations.

2.12 ISO 9001, ISO 14001, ISO 45001 management systems

ISO 9001 quality management, ISO 14001 environmental management and ISO 45001 occupational health and safety together form the systems-management envelope at every accredited Australian service centre. Documentation of HVAC parameters — capture velocity at every LEV hood, transport velocity in every dust main, total exhaust at each subsystem, scrubber and baghouse performance, stack-emission test results — feeds into ISO 14001 environmental record-keeping and ISO 45001 OHS record-keeping. ISO 9001 quality-management requirements drive documented HVAC parameter logging into the SCADA backbone.

2.13 AS/NZS 2107 acoustic, AS/NZS 1158 lighting, AS/NZS 1428.1 DDA, AS 1742 traffic

AS/NZS 2107 sets acoustic design targets — NC-45 office, NC-55 warehouse, NC-65 production area. AS/NZS 1158 sets lighting standards. AS/NZS 1428.1 covers disability-discrimination act access requirements for office, customer-counter and showroom areas. AS 1742 covers traffic-control signage including forklift movement areas and pedestrian-route segregation. Each is touched by the HVAC duct layout — ductwork must be routed to clear forklift swing paths (minimum 4.2 m clear height under duct), to clear AS/NZS 1428.1 disability-access routes through customer-counter areas, and to maintain AS/NZS 2107 acoustic targets through office-zone separating walls.

2.14 SafeWork Australia exposure standards — the chemistry-driven sizing inputs

SafeWork Australia’s workplace exposure standards (WES) are the regulatory inputs that drive LEV capture velocity and ductwork sizing. The service-centre-relevant standards are extensive and worth reading as a single block because they collectively explain why steel service centre HVAC is dimensioned the way it is:

• Manganese (Mn): 0.2 mg/m³ TWA. From welding fume on carbon and alloy steel, and from arc cutting of high-manganese steel.
• Iron oxide fume (Fe2O3): 5 mg/m³ inhalable, 10 mg/m³ respirable. From welding, oxy-fuel cutting, plasma cutting, laser cutting and slitting of carbon steel.
• Aluminium hydroxide / aluminium dust: 1 mg/m³ TWA respirable. CRITICAL for service centres — the dominant control for aluminium slitting, plasma and laser cutting, water-jet cutting and abrasive blasting of aluminium. NFPA 484 combustible-dust risk runs alongside the WES. Hydrogen evolution at wet collectors (Al + H2O reaction) is an additional hazard.
• Chromium hexavalent (Cr VI): 0.05 mg/m³ STEL. From stainless steel slitting, cutting (laser, plasma, water jet), grinding and welding. IARC Group 1 carcinogen. Lowest practical exposure standard in the service-centre work zone.
• Nickel (Ni inhalable): 1 mg/m³. Insoluble Ni compounds 0.1 mg/m³. From stainless steel and Inconel and Hastelloy cutting and welding.
• Lead (Pb): 0.05 mg/m³. From legacy leaded brass and leaded bearings (being phased out under Australian Pb-phase-out regulation but still present in some product lines).
• Copper fume (Cu): 0.2 mg/m³. From bronze and brass welding and cutting.
• Zinc oxide fume (ZnO): 5 mg/m³. CRITICAL for service centres — from cutting of galvanised steel (the zinc coating volatilises into fume at laser, plasma and oxy-fuel cutting temperature), and from welding of galvanised steel without prior zinc removal. Metal Fume Fever syndrome is a documented occupational hazard among service centre cutting operators.
• Cadmium (Cd): 0.01 mg/m³. From legacy cadmium-plated fasteners and components (being phased out).
• Beryllium (Be): 0.001 mg/m³ STEL. From copper-beryllium alloy springs and electrical connectors handled occasionally at specialty service centres.
• Carbon monoxide (CO): 30 ppm STEL. From LPG forklift exhaust, propane heating, plasma cutting, laser cutting combustion.
• Carbon dioxide (CO2): 5000 ppm. Indoor air quality marker; rises in poorly ventilated service-centre zones with LPG forklift activity and laser cutting.
• Nitrogen dioxide (NO2): 5 ppm STEL. From laser cutting plasma, CNC plasma cutting plasma, and oxy-fuel cutting combustion.
• Ozone (O3): 0.1 ppm STEL. From laser and plasma cutting plasma generation, and corona effects on high-voltage cutting torches.
• Hydrogen chloride (HCl): 5 ppm STEL. From legacy chemical treatment lines (being phased out at service centres but historically present).
• Hydrogen cyanide (HCN): 5 ppm STEL. From legacy cyanide-based plating (largely phased out at service-centre scale).
• Cutting fluid mist: 5 mg/m³ STEL inhalable. Water-based emulsion, oil-based, semi-synthetic and synthetic coolants. The dominant chronic-exposure marker at slitter lines and CTL lines.
• Oil mist: 5 mg/m³. Hydraulic oil and machine lubricant aerosol.
• Respirable dust: 5 mg/m³ respirable, 10 mg/m³ inhalable. Whole-of-air dust marker for metal swarf, abrasive blast grit, sand reclaim.
• VOC general: Paint solvent, thinner, adhesive, primer at pre-paint and packaging zones.
• Formaldehyde (HCHO): 1 ppm STEL. From phenolic resin in some packaging board and laminate.
• Hydrogen fluoride (HF): 1.8 ppm STEL. From aluminium and stainless pickling lines where present (upstream BlueScope and InfraBuild integrated mills handle pickling; some service centres operate a localised passivation tank).
• Refrigerant R32, R454B, R744 (CO2): Each is a regulated refrigerant in the office, control-room and showroom HVAC envelope.

Every dust, fume and mist LEV branch in a service centre has to keep the operator’s breathing-zone air below the relevant WES. Where multiple contaminants are present (Cr VI plus Ni plus Mn at a stainless laser cutting bed; AlOH3 plus deflagration risk plus oil mist at an aluminium slitter), the additive-mixture rule applies and the LEV must be sized to the lowest practical fraction. This is the calculation that drives capture velocity, transport velocity, branch sizing and main sizing across every service centre duct system.

3. Process zones — the steel service centre floor end-to-end

The most reliable way to specify steel service centre HVAC is to walk the process flow. Every Australian service centre maps to a variant of the same end-to-end sequence: inbound coil receipt and decoiler staging; uncoiling, levelling and straightening; slitting (rotary arbor with knife-stack); cut-to-length (precision shear with flying-shear stacker); profile roll-forming; tube-mill operations (Orrcon Steel and Austube Mills upstream); hydraulic shearing and CNC guillotine; CNC plasma cutting and CNC fibre-laser cutting; water-jet cutting; abrasive blasting and surface preparation; pre-paint and powder-coat; welding and assembly; QC inspection; packaging and shipping; and warehouse and racking. Each station has its own characteristic dust load, fume chemistry, temperature, capture velocity and material requirement.

3.1 Steel coil decoiler, uncoiler and leveller — the inbound staging

Master coils arrive by truck or rail to the service centre at 5 to 30 tonne mass, 25 to 2400 mm wide, 0.4 to 6.0 mm thick. Material covers the full Australian distribution range — DC galvanise Z275 to AS 1397, G300 grade galvanised, BlueScope Truecore framing steel, Colorbond pre-painted Colorbond Steel, Galvalume aluminium-zinc coated, Zincalume zinc-aluminium coated, AS 1449 stainless 304/316/316L, AS 1450 cold-rolled carbon steel, AS 1444 grade carbon, AS 1665-compliant aluminium 5052/5083/5086/6061/6082. The coil-handling area is the cleanest zone of the service centre, with the dominant HVAC demand being general dilution ventilation, plus localised LEV at the uncoiler where dust accumulated in storage shakes free during decoiling. Conventional galvanised duct to AS/NZS 4254 medium pressure is standard at 1.0 to 1.2 mm gauge. Aluminium coil handling needs separate dust collection isolation per NFPA 484 — aluminium coil edge dust accumulating in the uncoiler pit can ignite from a single static discharge.

3.2 Straightener and precision leveller — flatten and reduce internal stress

Precision levellers (Bradbury Magna Tech, Coilmaster, Burghardt, TJK) take the decoiled strip and pass it through a series of upper and lower work rolls under controlled tension, plastically deforming the strip cross-section to flatten residual coil set and reduce internal stress. The leveller is the heart of every flat-product service centre — without precision levelling, downstream cutting tolerance is unreliable. The leveller generates two LEV demands. First, leveller oil mist from the lubrication system flooding the work rolls — aerosol at 5 mg/m3 STEL captured at 0.3 to 0.5 m/s face velocity at the roll line, ducted in 316L stainless at 10 to 13 m/s transport to coalescer mist collector with electrostatic precipitator polish. Second, dust released from the strip surface during levelling — loose oxide, mill scale, packaging residue, prior-coil dust. Capture this at 1.0 m/s face velocity at the leveller exit, transport 18 to 22 m/s in galvanised or aluminised duct to baghouse.

3.3 Slitter line — rotary arbor with knife-stack, coil-to-slit dust extract

Coil slitter lines (rotary arbor Quintette, Schuler, Bradbury, TBA, with upper and lower knife stacks) take a master coil 25 to 2400 mm wide and slit it into multiple narrow strip coils. The slitter is the second-most-demanding HVAC station in any service centre after CNC cutting. The slitter operation generates three distinct LEV demands. First, coolant aerosol at the knife head from water-soluble coolant (Castrol, Houghton, Quaker Chemical, Master Chemical, Fuchs) flushing the swarf away from the knives — face velocity 0.5 m/s at the knife stack, transport 10 to 13 m/s in 316L stainless duct to coalescer mist collector. Second, slitting swarf at the bottom of the slitter — fine ribbon and curl of the slit edges. This is mechanically conveyed to the scrap pit rather than pneumatically extracted, but the dust generated as the swarf falls and accumulates is captured by a slot hood along the swarf-pit edge at 0.5 to 1.0 m/s and ducted in galvanised at 18 to 22 m/s to baghouse. Third, fine metallic particulate ejected at the knife shear-plane during slitting — ducted alongside the coolant aerosol but with additional filtration for solid-particulate capture. A BlueScope Distribution facility at Western Port VIC or Port Kembla NSW typically runs 3 to 6 slitter lines and 2 to 4 CTL lines in parallel — total LEV exhaust 60,000 to 150,000 m3/h with separate aerosol and swarf circuits. An InfraBuild Sydney slitter line for reinforcing bar handles 5 to 30 tonne master coils through 8 to 16 slit-strand outputs.

Aluminium slitting demands its own treatment. The slitter generates fine aluminium particulate below 75 micron at the knife shear-plane, classified as NFPA 484 Class ST3 combustible-metal dust. The aluminium slitter LEV must run in a separate circuit from carbon steel and stainless steel slitter LEV — no shared duct mains, no shared baghouse, no shared cyclone pre-separator. Mains in 316L stainless or aluminised steel at 1.0 to 1.2 mm gauge, bonded and grounded to building earth at less than 10 ohm continuous resistance per AS/NZS 60079, terminating at a wet-bath collector under permanent water flooding with hydrogen venting at the collector top. Capral Aluminium at Penrith NSW, Smithfield SA and other sites operates aluminium slitter lines for plate and sheet output to architectural, marine and structural customers, and each slitter line is a discrete NFPA 484 zone with annual dust hazard analysis.

3.4 Cut-to-length line — precision flying shear with leveller and stacker

Cut-to-length lines (Bradbury Magna Tech with precision optical thickness gauge, Coilmaster, Burghardt, TJK) take decoiled and levelled strip and cut to flat sheets at the customer-specified length. The CTL line integrates a precision leveller, an in-line flying shear or rotary cut-off shear, and an automated stacker delivering finished sheet to packaging. The CTL line generates three LEV demands similar to the slitter. First, leveller oil mist (same as section 3.2). Second, shear-drop dust at the cut — the moment the shear knife meets the sheet, fine metallic particulate is ejected from the cut zone. Capture velocity 1.0 m/s at the shear blade, transport 18 to 22 m/s in galvanised duct to baghouse. Third, residual coolant aerosol carried over from upstream slitting or processing. Total CTL exhaust is 5,000 to 15,000 m3/h per line. For BlueScope Distribution and InfraBuild flagship sites with 4 to 6 CTL lines in parallel, total exhaust runs 30,000 to 90,000 m3/h on the CTL hall alone.

3.5 Profile roll former and continuous roll forming — Lysaght, Stramit, Bradbury, Samco

Profile roll-forming takes flat coil through a multi-station roll former producing roof sheet (Lysaght Custom Orb, Trimdek, Lysaght Spandek, Stramit Monoclad, Trimdek, Stramit K-panel), wall sheet, structural section (Lysaght Mini-Rib, structural-section purlin), truss profile, SHS, RHS, CHS and precision tube. Bradbury, Samco, Tishken and JMP roll-formers are the dominant machinery brands. The HVAC envelope differs from flat-product service centre in three ways. First, roll-form oil mist — every station of the roll-former uses a thin coating of forming oil (vanishing oil, wax-stick lubricant, water-based forming fluid) that aerosolises under roll pressure. Total roll-form line generates an oil mist load at 5 mg/m3 STEL with face velocity 0.3 m/s at every station and dedicated 316L stainless or aluminised mist collection. Second, in-line cutting station — the formed profile is cut to length by flying shear, plasma cut or laser cut at the line exit, generating cut-station fume identical to flat-product cutting but with the additional complication of integrated line operation (can’t shut down cut station without shutting down the whole line). Third, post-cure paint and coating — Lysaght’s Coomera plant and several Stramit lines integrate post-form paint or powder-coat curing at 200 degC, falling under NFPA 86 industrial oven with dedicated VOC and isocyanate exhaust, dedicated 316L cure-oven exhaust to thermal oxidiser. The HVAC envelope is integrated rather than zone-by-zone — every disturbance shuts down the whole line. Apex Steel and Apex Engineered Solutions run similar continuous roll-forming for structural sections and architectural profiles.

3.6 Tube mill — Orrcon, Austube, RHS, SHS, CHS, precision tube

Tube mills convert flat strip into welded round, square or rectangular tube by a continuous roll-form and weld process. Orrcon Steel (BlueScope subsidiary at Brisbane, Sydney, Melbourne and Perth) and Austube Mills (BlueScope and Manyalo merged, Sunshine VIC + Newcastle NSW + Welshpool WA) are the dominant Australian tube mill operators producing RHS rectangular hollow section, SHS square hollow section, CHS circular hollow section to AS 1163 structural grade and AS 1450 precision-tube grade. Tube mill HVAC has three dominant LEV demands. First, roll-form oil mist (as section 3.5). Second, weld-line fume at the longitudinal seam weld — the tube is roll-formed into round profile and the open seam is closed by induction or arc weld, generating heavy iron-oxide fume (Fe2O3 5 mg/m3 inhalable) at the weld zone. Capture velocity 1.0 m/s at the weld station, transport 18 to 22 m/s in galvanised duct to baghouse. Third, post-weld cooling and sizing — the welded tube is cooled by water spray and rolled to final dimension by sizing rolls. The water-spray-cooling generates atmospheric humidity that the HVAC must manage to prevent corrosion of adjacent unfinished tube. Austube Mills at Sunshine VIC and Welshpool WA, and Orrcon Steel at Brisbane and Sydney, each run tube mill HVAC envelopes of 50,000 to 200,000 m3/h.

Stainless tube production at Atlas Steels and at specialist stainless service centres uses the same tube mill technology but with hardened tooling and Cr VI fume management. The stainless tube weld station is a dedicated Cr VI source — the welding of 304 or 316 stainless seams generates Cr VI in the weld fume, requiring 316L stainless mains, dedicated Cr VI baghouse, and continuous Cr VI emissions monitoring at facilities above 50 tonne monthly stainless throughput.

3.7 Hydraulic shear and CNC guillotine — manual cut of flat plate

Hydraulic shears and CNC guillotines (UpMax, Adira, Boschert, Salvagnini, Ermak) cut flat plate up to 25 mm thickness in mild steel, 16 mm in stainless, 20 mm in aluminium. The shear is a mechanical cutting station with no thermal cutting fume — the LEV demand is limited to shear-drop dust at the cut moment, similar to CTL section 3.4. Capture velocity 1.0 m/s at the shear blade, transport 18 to 22 m/s in galvanised duct to baghouse. Total exhaust at a manual hydraulic shear station is 2,000 to 5,000 m3/h. Multi-bay shearing halls at large service centres (InfraBuild Sydney, Apex Engineered Solutions) may run 6 to 12 shear stations in parallel.

3.8 CNC plasma cutting — Hypertherm, Lincoln Electric at 100 to 400 A

CNC plasma cutting (Hypertherm HD plasma, Lincoln Electric Tomahawk, Kjellberg Q-Series, ESAB Hydrocut) is the workhorse thermal cutting technology for service centre cut-to-shape work in carbon steel, stainless and aluminium plate from 6 mm to 50 mm thickness. Plasma operates at 100 to 400 A current with a high-velocity ionised plasma jet at 20,000 to 30,000 degC. The cutting plasma generates a complex chemistry mix: heavy particulate (iron oxide, manganese, chromium, nickel depending on workpiece alloy), nano-particulate metallic aerosol below 1 micron, ozone (O3 0.1 ppm STEL) and NO2 (5 ppm STEL) from atmospheric nitrogen oxidation, CO (30 ppm STEL) from incomplete combustion, and Cr VI hexavalent chromium on stainless workpieces. Plasma is louder than laser — 110 to 120 dBA at the nozzle without enclosure — requiring hearing protection in the cutting hall.

Plasma cutting LEV is dedicated downdraft tables with zone-isolation along the bed length. The cutting bed is divided into 1.5 to 2.5 m long zones, each with an independent damper that opens only for the cut zone underway, concentrating the LEV airflow on the active cut. Face velocity at the bed slot 1.5 to 2.0 m/s, transport velocity 18 to 22 m/s in 316L stainless mains where Cr VI or aluminium is present, in aluminised steel where carbon steel only. Dedicated cartridge or pulse-jet baghouse with HEPA polish on the stack discharge. Australian state EPA stack-emission licences at large service centres cap PM10, PM2.5, NO2, Cr VI and Ni concentrations and require continuous emissions monitoring above 50 tonnes monthly stainless or aluminium throughput. Total LEV at a 3 m by 6 m plasma cutting bed is typically 20,000 to 40,000 m3/h.

3.9 CNC fibre-laser cutting — Bystronic, Trumpf, Mazak, Mitsubishi, Amada at 6 to 12 kW

CNC fibre-laser cutting (Bystronic ByStar Fiber, Trumpf TruLaser, Mazak Optiplex, Mitsubishi MV, Amada Ensis) at 6 kW to 12 kW power is the precision thermal cutting technology for service centre cut-to-shape work in carbon steel, stainless and aluminium plate up to 25 to 50 mm. The laser cuts via focused infrared beam vaporising the material, with an oxygen (carbon steel) or nitrogen (stainless, aluminium) assist gas blowing the molten cut-zone metal out of the kerf. Compared to plasma, laser produces a narrower kerf, higher edge quality, lower distortion and significantly less audible noise. The cutting fume chemistry is broadly similar to plasma but with finer particulate (nano-particulate aerosol dominates below 0.5 micron diameter) and lower NO2 and ozone at equivalent throughput.

Laser cutting of carbon steel releases iron oxide fume (Fe2O3 5 mg/m3 inhalable WES) and nano-particulate aerosol. Laser cutting of stainless steel releases Cr VI (0.05 mg/m3 STEL) plus Ni inhalable (1 mg/m3) plus the same nano-particulate. Laser cutting of galvanised steel volatilises zinc into ZnO fume (5 mg/m3). Laser cutting of aluminium releases AlOH3 dust (1 mg/m3) and creates fine-particle metallic dust under NFPA 484 jurisdiction. The LEV solution mirrors plasma — dedicated downdraft tables with zone-isolation, 316L stainless mains where Cr VI or aluminium is present, dedicated baghouse with HEPA polish, continuous emissions monitoring at large sites. Laser cutting halls additionally require chiller LEV for the laser tube cooling system (closed-loop chilled water through the fibre source).

3.10 Water-jet cutting — Flow, OMAX, Mistral, Bohle at 60,000 psi / 4,000 bar

Abrasive water-jet cutting (Flow, OMAX, Mistral, Bohle) uses ultra-high-pressure water at 60,000 psi (4,000 bar) entraining garnet abrasive grit to cut any material including stainless, aluminium, copper, titanium and stack-laminated composites. Water-jet has no thermal cutting fume — the cut is cold — but generates two distinct LEV demands. First, water-aerosol mist at the cutting head from the high-pressure water spray rebounding off the workpiece — aerosol at 5 mg/m3 STEL captured at 0.3 to 0.5 m/s face velocity at the cutting head, ducted in 316L stainless at 10 to 13 m/s to coalescer mist collector. Second, silica dust risk from the garnet abrasive carrying RCS contamination — the abrasive sand return tray needs its own dedicated dust extraction in addition to the aerosol mist extraction. Garnet abrasive consumption is significant (0.5 to 1.0 kg per minute of cutting at higher pressures), and the spent garnet is contaminated with cut-material particulate. Disposal is under state EPA solid-waste licence.

3.11 Abrasive water jet with grit, sand blast and pre-paint preparation

Abrasive blasting (BlastOne, Wheelabrator, Pangborn) uses steel grit, iron shot, aluminium oxide, garnet, glass bead or silica sand (the latter being increasingly replaced by aluminium oxide on RCS grounds) propelled at 60 to 80 m/s to clean and prepare metal surface before paint or powder coat. The blast cabinet generates the heaviest dust load in any service centre operation — cabinet interior at 0.5 m/s face velocity at the work aperture, dust main at 18 to 22 m/s transport velocity in galvanised or wear-lined duct to cyclone pre-separation followed by baghouse. Where heavy lead bullets are used for legacy lead-paint removal (occasional at specialty rework operations), the blast cabinet is a Pb-controlled zone with operator P3 respirator and dedicated Pb baghouse and continuous Pb air monitoring against the 0.05 mg/m3 WES.

3.12 Pre-paint and powder coat — Akzo Nobel, Dulux, Jotun, Tiger, IGI, PPG

Pre-paint and powder coat operations at integrated service centres include chromate-conversion legacy treatment (Iridite, Alodine — being phased out under Australian Cr VI phase-out rules to trivalent chromium TCP, sulfuric anodise SAA, tartaric sulfuric anodise TSA and boric sulfuric anodise BSAA), powder-coat oven cure at 200 degC for 20 minutes, and conventional liquid paint application by spray, dip or coil-coating. Major paint and powder coat suppliers are Akzo Nobel (Interpon powder), Dulux Powder, Jotun, Tiger Coatings, IGI and PPG. The HVAC envelope at the paint and cure stations includes paint-spray-booth LEV at 0.5 to 0.7 m/s face velocity across the booth opening, ducted in galvanised to dry filter or water-curtain pre-separation followed by carbon-bed VOC adsorption. Powder-coat booth LEV is broadly similar but with the recovered overspray returned to the gun hopper for reuse. The 200 degC powder-coat cure oven falls under NFPA 86, with dedicated exhaust riser in aluminised steel at 1.2 to 1.5 mm gauge, LEL monitoring at the burner, and explosion venting on the oven shell.

3.13 Welding and joining — TIG, MIG/MAG, SMAW, oxy-acetylene, laser welding, robotic welding

Service centre welding (in-house duct fabrication, customer cut-and-weld services, rack and pallet fabrication, custom assembly) uses TIG (GTAW), MIG/MAG (GMAW), SMAW (stick), oxy-acetylene, laser welding and robotic welding cells. Welding fume chemistry depends on base metal and filler — mild steel welding generates Mn (0.2 mg/m3) and Fe2O3 (5 mg/m3); stainless welding generates Cr VI (0.05 mg/m3), Ni (1 mg/m3) and Mn; aluminium welding generates AlOH3 (1 mg/m3); leaded brass welding generates Pb (0.05 mg/m3) and Cu (0.2 mg/m3). AS/NZS 4453 mandates on-tool extraction (welding-gun fume extraction) plus local downdraft hood or swivel-arm overhead at every welding bay. UV and IR shielding by welding curtain. 316L stainless mains for Cr VI fume streams to dedicated baghouse with HEPA polish; aluminised steel for general carbon-steel welding fume to baghouse. Robotic welding cells (KUKA, ABB, Yaskawa, Fanuc) are fully enclosed with integrated LEV at the cell ceiling.

3.14 QC inspection — X-ray RT, ultrasonic UT, dye penetrant DPI, magnetic particle MPI

Quality control inspection at service centres includes X-ray radiography (RT) on welded fabrication, ultrasonic testing (UT) on plate and tube, dye penetrant inspection (DPI) on welds and machined surfaces, magnetic particle inspection (MPI) on ferromagnetic components, hardness testing (Rockwell, Brinell), tensile testing and chemistry verification (XRF handheld, spark emission spectrometer at sample lab). The QC lab has its own HVAC envelope — conditioned air to NC-45, supply 316L stainless or hot-dip galvanised, dedicated exhaust at the spark-emission spectrometer (argon shield gas exhaust plus minor metallic fume from spark stand). The X-ray RT room is a lead-shielded enclosure with dedicated supply-air HEPA-filtered conditioning to maintain stable temperature for imaging electronics.

3.15 Packaging, shipping, slab and coil handler, OS crane, truck, rail, road train, container

Outbound packaging and shipping is the cleanest part of the service centre, with the dominant HVAC demand being general dilution ventilation. LPG-forklift activity is concentrated in this zone, driving the AS/NZS 60079 Zone 2 hazardous-area envelope for the LPG bottle exchange and forklift refuelling stations. Ducted ventilation in the LPG zone is in aluminised steel at 1.2 mm with Ex-rated supply-air fans and Ex-rated zone-area lighting. Customs and export packing at the international shipping bay (ATA Carnet for exhibition equipment, full customs documentation for export) uses general dilution ventilation in conventional galvanised duct.

3.16 Warehouse, racking, saw, band saw, chop saw, HSS cold saw, CNC drill, CNC punch

The warehouse and racking zone houses inventory plus mechanical cutting equipment — band saw, chop saw, HSS cold saw, CNC drill press, CNC punch press (Trumpf TruPunch, Amada Vipros). Each saw and drill station is an LEV source with localised dust collection at 0.5 to 1.0 m/s face velocity, transport 18 to 22 m/s in galvanised duct to baghouse. CNC punching of coated coil at high cycle rates can generate significant zinc fume if the coil is hot-galvanised — ZnO 5 mg/m3 STEL drives dedicated LEV at high-throughput punch stations.

3.17 Admin, showroom, sales, engineering, CAD, project management

The office, customer-counter showroom, sales floor and engineering CAD area form the clean envelope of the service centre. HVAC is conventional supply-and-return at NC-45 (AS/NZS 2107 office target) in 0.8 to 1.0 mm galvanised duct to AS/NZS 4254 low-pressure standards. Slight positive pressure relative to the production hall prevents cross-contamination of office air with welding fume, cutting fume or coolant aerosol. The customer-counter showroom additionally requires AS/NZS 1428.1 disability-access compliance and AS/NZS 1158 lighting compliance, with the HVAC return-air diffusers positioned to clear pedestrian routes.

4. Material selection — why galvanised works for most service centre HVAC and where stainless takes over

Galvanised duct is the workhorse of HVAC fabrication. Across data centres, commercial towers, hospitals and schools, hot-dip-galvanised carbon steel sheet to AS 1397 and AS/NZS 4254 is the right answer for 95% of duct work. In a steel service centre, galvanised remains the right answer for around 70% of the duct, with 316L stainless taking over in five specific applications: Cr VI laser and plasma cutting fume mains on stainless workpieces; aluminium NFPA 484 dust mains; HF pickling exhaust where present; coolant aerosol mist mains; and clean make-up air supply to QC laboratory and inspection rooms.

4.1 Hot-dip galvanised carbon steel to AS 1397 — the service centre workhorse

Z275 hot-dip galvanised carbon steel to AS 1397 (275 g/m2 total both sides) is the standard service centre duct material for carbon-steel cutting fume mains, slitter swarf transport, CTL shear-drop dust, hydraulic-shear dust, abrasive blast cabinet extract (where blast media is carbon steel grit or iron shot), paint-spray-booth pre-separation, packaging area dilution ventilation and warehouse general ventilation. Galvanised gives 25-year service life at ambient temperature in dry conditions, 10 to 15 years in slightly humid or condensing conditions. Service temperature limit is 200 degC continuous (zinc fume forms above 250 degC) — well within the operating envelope of service-centre cutting fume mains downstream of the immediate cutting torch zone.

4.2 Hot-dip aluminised steel — medium-temperature applications

Hot-dip aluminised steel (carbon steel coated with aluminium-silicon alloy) gives extended service life in mildly corrosive and elevated-temperature service. At service centres, aluminised steel is used for plasma and laser cutting fume mains immediately downstream of the cutting bed where local temperature can spike to 300 to 400 degC, for pre-paint and powder-coat cure oven exhaust at 200 to 250 degC, and for any duct passing close to galvanise kettle exhaust (450 degC) at integrated coater operations. Aluminised steel is also the practical material for paint-coated coil distribution at BlueScope Distribution — the aluminised coating avoids zinc-fume cross-contamination at any in-line cutting that might affect adjacent Truecore or Colorbond coil.

4.3 316L stainless steel — Cr VI, NFPA 484, HF and coolant streams

316L stainless to AS 1449 (Cr 16 to 18 percent, Ni 10 to 14 percent, Mo 2 to 3 percent, C maximum 0.03 percent) is the chemistry-resistant duct material for service centre HVAC. Five specific applications drive 316L specification:

• Cr VI laser and plasma cutting fume mains: Stainless workpieces under laser and plasma cutting generate Cr VI in the cutting fume. The duct must withstand Cr VI scrubber chemistry and the hygroscopic Cr VI particulate that condenses on cool duct walls. 316L gives 30-year service life.
• Aluminium NFPA 484 dust mains: Aluminium dust extraction circuits must be bonded and grounded to AS/NZS 60079, with the duct shell carrying the bond. 316L stainless or aluminised steel both qualify; 316L gives the longest service life in wet-collector inlet duct.
• HF pickling exhaust: Where the service centre operates a localised passivation or pickling tank (rare at distribution scale but present at specialty service centres handling stainless re-finish work), HF 1.8 ppm STEL drives 316L stainless mains with dedicated caustic scrubber.
• Coolant aerosol mist mains: Water-soluble coolant aerosol contains biocide, surfactant and emulsified oil at 5 to 8 pH. 316L gives long service life against the chemistry; galvanised fails in 3 to 5 years in coolant-aerosol service.
• Clean make-up air supply: QC laboratory, X-ray inspection room and customer-counter showroom supply-air mains run in 316L stainless or hot-dip galvanised for clean make-up zones with HEPA pre-filters at the supply diffusers.

4.4 Wear-lined and hardfaced construction — the highest-abrasion zones

Where abrasion is extreme — the discharge of the slitter swarf conveyor, the first elbow downstream of the abrasive blast cabinet, the primary classifier inlet of large baghouses — bare-metal duct (galvanised, aluminised, or 316L) wears through in 1 to 3 years. Wear-lined construction extends service life to 10 to 20 years. Three options:

• Hardox patch panels: 6 to 12 mm Hardox 450 or Hardox 500 plate welded into the duct interior at high-wear locations. Bisalloy 400 or Bisalloy 500 from Bisalloy Steels Unanderra NSW is the local-source equivalent.
• Ceramic tile lining: Alumina ceramic tiles bonded to the duct interior with high-temperature epoxy or mechanical fixings. Heaviest wear resistance, highest cost.
• Hardfaced cladding: Tungsten-carbide or chrome-carbide overlay welded onto the duct interior at field locations for patch-repair of worn duct in service.

4.5 FRP and acid-resistant coatings — scrubber outlets

The clean side of a wet scrubber — between the demister and the discharge stack — carries saturated air at near-ambient temperature with potential acid carryover. Fibre-reinforced plastic (FRP) ducting or epoxy-coated carbon steel is the standard solution. FRP is corrosion-immune and lightweight but is non-conducting; for any duct in a combustible-aluminium-dust zone, bonding and grounding requires conductive carbon-fibre additive or external bonding tape.

5. Sizing and design — capture velocity, transport velocity, acoustic targets

5.1 Capture velocity at the source

Capture velocity is the air-flow speed required at the dust or fume source to entrain contaminant into the hood. ACGIH Industrial Ventilation Manual values, used in Australian practice alongside AS 1668.2:

• Low-velocity dust release (welding fume, leveller-line dust): 0.25 to 0.5 m/s
• Active dust release in moving air (slitter knife, CTL shear, hydraulic shear, saw): 0.5 to 1.0 m/s
• High-velocity dust release (plasma cutting bed, laser cutting bed, abrasive blast cabinet): 1.0 to 2.0 m/s
• Plasma and laser cutting bed slot face velocity: 1.5 to 2.0 m/s
• Coolant aerosol mist capture at slitter knife, CTL leveller, roll-former stations: 0.3 to 0.5 m/s
• Powder-coat cure-oven canopy: 1.0 m/s at oven door

5.2 Transport velocity in the duct

Transport velocity is the in-duct air speed required to keep captured contaminant in suspension. Below transport velocity, dust drops out and accumulates in horizontal runs; above, abrasive wear accelerates and noise rises.

• Vapour, fume and very fine dust (welding fume, paint mist, laser nano-particulate): 10 to 13 m/s
• Coolant aerosol and oil mist (slitter, CTL leveller, roll-form, machining): 10 to 13 m/s
• Fine dust (pattern shop dust, ambient woodworking, lab spectrometer exhaust): 13 to 18 m/s
• Medium dust (general cutting fume mains, abrasive blast cabinet downstream of cyclone): 18 to 20 m/s
• Heavy dust (slitter swarf, CTL shear-drop, abrasive blast cabinet cyclone inlet): 20 to 22 m/s
• Very heavy abrasive material (metal turnings from CNC machining, plasma kerf slag, slitter ribbon): 22 to 25 m/s with wear-lined construction

5.3 Hood geometry

Hood selection is process-driven. Downdraft tables underneath plasma and laser cutting beds with zone-isolation along the bed length. Slot hoods alongside slitter swarf pit edges and CTL shear-drop chutes. Side-draft canopies above hydraulic shears and CNC guillotines. Coolant aerosol capture trays beneath slitter knife heads and CTL leveller rolls. Welding-bay overhead swivel-arm or wall-mounted slot hoods, with on-tool gun extraction supplementing for high-volume MIG/MAG work. Powder-coat booth open-front with cross-draft return at the back wall. Abrasive blast cabinet sealed enclosure with negative pressure and viewing window.

5.4 Acoustic targets — AS/NZS 2107 service centre zones

Service centre acoustic design follows AS/NZS 2107. Production hall (cutting, slitting, CTL, welding, abrasive blast) is NC-65 with mandatory hearing protection. Warehouse and racking NC-55. Customer-counter showroom and sales NC-50. Office and engineering CAD NC-45. Acoustic lagging on exhaust mains passing near manned workstations, NC-rated supply-air attenuators in office and lab branches, and sound-rated wall penetrations between production and office zones are standard practice. Plasma and laser cutting halls additionally have full or partial acoustic enclosures around the cutting bed to reduce the 110 to 120 dBA cutting noise to the 85 dBA hearing-protection threshold.

6. The Australian steel service centre market — operator-by-operator HVAC snapshot

The Australian steel service centre and metals distribution sector is concentrated in a smaller number of larger operators than it was twenty years ago, with strong specialisation by metal type, coil grade and end market. The operators below cover the bulk of mainland Australian distribution and reflect the range of HVAC demands a Box Hill North VIC-based machine supplier sees in the field.

6.1 BlueScope Distribution — Western Port VIC + Port Kembla NSW

BlueScope Distribution is BlueScope’s own coated-coil distribution arm, operating major service centres at Western Port VIC and Port Kembla NSW with smaller distribution depots across the country. The product mix is BlueScope’s own coated coil — Truecore Activate structural framing steel, Colorbond pre-painted Colorbond Steel (in multiple thickness and colour ranges), Galvalume aluminium-zinc 55%Al-43.4%Zn-1.6%Si, and Zincalume zinc-aluminium 55%Al-43.5%Zn-1.5%Si — distributed to fabricators and roof-and-wall contractors across the country. The HVAC stack at BlueScope Distribution is dominated by slitter and CTL lines for coated coil, with careful coolant management to avoid paint contamination of Colorbond and Truecore product. Mains are aluminised steel rather than galvanised to avoid zinc-fume cross-contamination at any in-line cutting. Total LEV at Western Port VIC and Port Kembla NSW combined runs 200,000 to 300,000 m3/h across coil-handling, slitter and CTL halls plus downstream packaging.

6.2 InfraBuild Wire and Distribution — Sydney HQ, Whyalla SA EAF, national service centres

InfraBuild (formerly OneSteel Distribution, now under GFG Alliance Liberty Steel ownership with the Sanjeev Gupta group) is Australia’s biggest steel distributor by tonnage. Headquartered at Sydney with the EAF reinforcing bar mill at Whyalla SA, plus distribution service centres at Sydney + Melbourne + Brisbane + Newcastle + regional capitals. Product mix includes EAF rebar (reinforcing bar to AS/NZS 4671), merchant bar (rod, square, flat), structural section (universal beam, column, channel, angle to AS/NZS 3679), wire (to InfraBuild Wire at Newcastle + Geelong producing wire rod, mesh, barbed wire, chain link), and distribution of third-party imported and local-mill carbon steel coil and plate. The HVAC stack at InfraBuild service centres is the heaviest carbon steel slitting and CTL volume in the country — large-coil rotary slitters and CTL lines, with conventional galvanised LEV at 18 to 22 m/s for shear-drop dust and oil mist, conventional plasma and laser cutting fume LEV, and large warehouse and racking with general dilution ventilation. Total LEV at InfraBuild Sydney runs 100,000 to 200,000 m3/h.

6.3 Lysaght — Coomera QLD + Sydney + Melbourne + Brisbane + Perth + Adelaide + Darwin

Lysaght is a BlueScope subsidiary running pre-engineered roofing, walling and structural-section roll-forming from seven Australian sites — Coomera QLD (flagship), Sydney, Melbourne, Brisbane, Perth, Adelaide and Darwin. Lysaght output is the Lysaght-brand roofing (Custom Orb, Trimdek, Spandek, Klip-Lok), walling (Mini-Rib, Multiclad), and structural section (Mini-Web, Topspan purlin, Bondek decking). The HVAC envelope at each Lysaght plant is dominated by roll-form oil mist (every station of the continuous roll-former), in-line cutting at the line exit (flying shear or plasma cut), and at Coomera and several other sites, integrated post-form paint or powder-coat cure at 200 degC under NFPA 86. Total LEV at Lysaght Coomera runs 80,000 to 150,000 m3/h.

6.4 Stramit — CSR ASX:CSR-owned roofing and walling

Stramit (CSR ASX:CSR-owned) operates roll-formed roofing and walling distribution and fabrication. Product mix is Stramit Monoclad, Stramit Trimdek, Stramit Tuffcote, Stramit K-panel, Stramit COLORBOND-roof, Stramit purlin. The HVAC envelope mirrors Lysaght with continuous roll-form oil mist, in-line cutting fume, and post-form paint or powder-coat cure where integrated.

6.5 Apex Steel + Apex Engineered Solutions

Apex Steel and Apex Engineered Solutions are independent service centre operators handling structural-section distribution, plate distribution and engineered cut-and-bend fabrication for the construction sector. The HVAC envelope is mid-scale slitter and CTL plus plasma cutting plus structural welding fabrication.

6.6 NPS Stores — Sydney + Melbourne + Brisbane + Adelaide + Perth national stockist

NPS Stores operate a national stockist network with sites at Sydney, Melbourne, Brisbane, Adelaide and Perth. Smaller per-site footprint than BlueScope Distribution or InfraBuild but covering the same flat-product distribution market. HVAC envelope is conventional slitter and CTL with conventional plasma cutting and warehouse dilution.

6.7 Coil Steels NSW, Northern Iron and Brass Brisbane, Eastern + Welcome + Pacific + Atlantic + Continental + Champion + Global Steel

Coil Steels NSW operates regional coil distribution. Northern Iron and Brass at Brisbane covers iron and brass distribution. The remaining names — Eastern Steel, Welcome Steel, Pacific Steel, Atlantic Steel, Continental Steel, Champion Steel, Global Steel, Sheet Metal Suppliers — cover the independent regional service centre network. Each runs a smaller-scale variant of the BlueScope Distribution or InfraBuild HVAC envelope, with 20,000 to 80,000 m3/h total LEV depending on throughput.

6.8 Atlas Steels — Carlton VIC stainless and special-alloy flagship

Atlas Steels at Carlton VIC is Australia’s biggest stainless and special-alloy distributor. Product mix is the full stainless range — 304, 316, 316L, 440, 13Cr martensitic, duplex 2205, duplex 2304, 317L, 904L — plus super-alloy distribution covering Inconel 625, Inconel 718, Hastelloy C-276, Monel, Nitronic 50, Nitronic 60, titanium and additional specialty alloys. Atlas operates plate, sheet, coil, bar, tube and structural-section distribution to the food, medical, marine, defence, mining-wear, aerospace and chemical-process industries. The HVAC stack at Atlas Carlton is the most demanding in the Australian distribution sector — Cr VI control on every cutting station, dedicated 316L stainless mains throughout the cutting and slitting hall, separated hardened tooling to prevent alloy cross-contamination, and separate dust collection circuits for stainless versus aluminium versus carbon steel under NFPA 484 separation rules. Cr VI continuous emissions monitoring is mandatory at the Atlas stack discharge.

6.9 Australian Stainless Service Centre ASSC — Sydney + Melbourne + Brisbane + Perth

Australian Stainless Service Centre (ASSC) operates stainless distribution at four sites — Sydney, Melbourne, Brisbane and Perth. Product mix is commodity stainless — 304, 316, 316L, 409 (automotive exhaust grade), 430 (ferritic decorative). HVAC envelope is dedicated Cr VI stainless cutting and slitting mains in 316L to dedicated Cr VI baghouse, plus general distribution ventilation.

6.10 Suntech Steel Service Centre — 304/316/duplex

Suntech Steel operates stainless distribution at smaller scale than ASSC and Atlas, handling 304, 316 and duplex 2205. HVAC envelope is conventional stainless service-centre design with 316L Cr VI mains.

6.11 Capral Aluminium ASX:CAA — Penrith NSW + Bremer Park QLD + Smithfield SA + Welshpool WA national flagship

Capral Aluminium (ASX:CAA) is Australia’s biggest aluminium distributor, operating manufacturing and distribution sites at Penrith NSW (flagship extrusion + sheet + plate), Bremer Park QLD, Smithfield SA, Welshpool WA, Crestmead, Bayswater, Sumner and Wollongong. Product mix is billet (cast-house product), plate (5052, 5083, 5086 structural and marine; 6061, 6082 structural), sheet (full thickness range), extrusion (architectural section profile), and finished architectural product (window and door systems). The HVAC stack at Capral is the most demanding NFPA 484 envelope in the Australian distribution sector — every aluminium slitter, CTL line, plasma cutter, laser cutter, water-jet cutter and abrasive-blast cabinet is a discrete NFPA 484 zone with annual dust hazard analysis. Mains run in 316L stainless with full bonding and grounding across every flange, terminating at wet-bath collectors under permanent water flooding with hydrogen venting. Total LEV at Capral Penrith runs 80,000 to 150,000 m3/h on the aluminium production and distribution hall.

6.12 Aluminium Specialties, AluCobond, AWS, BCI

Aluminium Specialties operates as secondary aluminium distribution alongside Capral. AluCobond manufactures aluminium composite panel (ACP) for facade cladding. Architectural Window Systems (AWS) and Bonded Composites Industries (BCI) operate architectural aluminium fabrication. The HVAC envelope mirrors Capral on smaller scale.

6.13 Orrcon Steel — BlueScope subsidiary, RHS + SHS + CHS tube

Orrcon Steel is a BlueScope subsidiary running tube-mill production of RHS rectangular hollow section, SHS square hollow section, CHS circular hollow section to AS 1163 structural grade, plus precision tube. Tube mill HVAC includes roll-form oil mist, induction or arc weld-line fume, post-weld water-spray cooling humidity management, and downstream cut-to-length flying shear.

6.14 Austube Mills — BlueScope + Manyalo merged Sunshine VIC + Newcastle NSW + Welshpool WA

Austube Mills is the BlueScope and Manyalo merged tube-mill operation at Sunshine VIC, Newcastle NSW and Welshpool WA. Output is RHS, SHS, precision tubing. HVAC envelope is integrated tube-mill at each site with weld-line LEV, oil-mist LEV, sizing roll cooling humidity, and downstream cut-to-length.

6.15 Bisalloy Steels ASX:BIS — Unanderra NSW quenched and tempered plate

Bisalloy Steels at Unanderra NSW manufactures quenched-and-tempered armour, wear-resistant and structural plate to specialty grades (Bisalloy 80, 320, 360, 400, 450, 500). The HVAC envelope includes a Q&T heat-treatment line (NFPA 86 oven exhaust at 800 to 1000 degC), oil-quench tank LEV for the quench-oil fume, and plate-handling general ventilation.

6.16 InfraBuild Wire, Riverina Wire Industries, Newland Steel Australia

InfraBuild Wire at Newcastle and Geelong produces wire rod, mesh, barbed wire and chain link from EAF rod feedstock. Riverina Wire Industries and Newland Steel Australia operate at smaller scale. Wire production HVAC includes pickling-line exhaust (where HCl or H2SO4 pickling is integrated), wire-drawing soap-mist LEV, and coating-line exhaust.

6.17 Tomago Aluminium — Newcastle primary smelter (separate from secondary distribution)

Tomago Aluminium at Newcastle NSW operates a primary aluminium smelter (Hall-Heroult cell pot-line, anode bake, casthouse). HVAC at Tomago is the heaviest aluminium HVAC envelope in the country with HF cryolite cell-pot exhaust, anode-bake fume, and casthouse pour-station LEV. Tomago is upstream of the distribution segment but feeds Capral and the secondary aluminium market.

6.18 What the operator mix means for fabricators

The Australian steel service centre and metals distribution market is not a single homogeneous segment. BlueScope Distribution needs coated-coil-specific HVAC with paint-contamination management. InfraBuild needs the heaviest carbon-steel slitter and CTL HVAC by tonnage. Lysaght and Stramit need integrated roll-form and post-form paint cure HVAC. Atlas Steels needs the most demanding Cr VI stainless HVAC. Capral Aluminium needs the most demanding NFPA 484 aluminium HVAC. Orrcon and Austube need tube-mill weld-line HVAC. Bisalloy needs Q&T heat-treatment NFPA 86 HVAC. Each operator drives a different mix of duct material, duct geometry and capture-hood design. A fabricator equipped to serve all of them with SBKJ machinery is positioned to capture meaningful market share across the Australian distribution sector.

7. The baghouse, mist collector and scrubber interface

Almost every service centre exhaust stream terminates at a baghouse, mist collector, scrubber or thermal oxidiser, or a combination of the four. The selection between them is process- and chemistry-driven.

7.1 Baghouses — pulse-jet cartridge and bag

Baghouses use fabric filter elements (polyester, aramid Nomex, PTFE membrane, fibreglass) or pleated cartridge filters to capture dust mechanically. They are the preferred choice for dry non-combustible dust streams (slitter swarf, CTL shear-drop, plasma kerf, laser cutting fume on carbon steel, abrasive blast cabinet downstream of cyclone) and offer high collection efficiency (99.5% plus on particulate) with no water consumption. Disadvantages are filter-bag life (12 to 36 months depending on dust load), temperature limit (polyester bags fail above 130 degC, Nomex above 200 degC, PTFE membrane above 250 degC), and explosion-protection requirements for any combustible-dust application.

Duct-side considerations at the baghouse inlet are temperature — the duct must cool the exhaust to below the bag’s service temperature, typically by passing through evaporative cooler or simply allowing radiation cooling along the duct length. NFPA 660 isolation valves between baghouse and inbound duct prevent baghouse fire from propagating back through the duct. Bonded-and-grounded construction on every metre of inbound duct prevents static discharge ignition.

7.2 Cartridge collectors — pleated media, compact footprint

Cartridge collectors (Donaldson Torit, Camfil, Camcorp) use pleated paper or synthetic media cartridges in a compact housing, well-suited to cutting-fume capture at single plasma or laser bed installations. Lower dust-holding capacity than full baghouse but smaller footprint and easier installation in tight service-centre cutting halls.

7.3 Mist collectors — coalescer and electrostatic precipitator

Coolant aerosol and oil mist capture uses coalescer-filter mist collectors (Donaldson Torit-IRD, Aircell, Filtermist, Mist-Out) with electrostatic precipitator polish. The collector inlet duct is 316L stainless at 10 to 13 m/s transport velocity, with the collector itself sized for 5 to 25 m3/min per machine source. Multiple slitter and CTL stations can share a common mist collector with branched inlet duct.

7.4 Wet scrubbers — for HF, aluminium NFPA 484, and where required

Wet scrubbers pass exhaust through water spray that captures particulate and absorbs water-soluble gas. They are mandatory for fine aluminium dust under NFPA 484, required for HF exhaust (where present at pickling or passivation), and used where stack-emission licence requires very low particulate output. The wet-bath collector for aluminium dust uses caustic-neutral or slightly alkaline water bath with hydrogen venting at the collector top (Al + H2O reduces water to H2 gas at elevated bath temperature).

7.5 Thermal and catalytic oxidisers

Regenerative thermal oxidisers (RTO) and catalytic oxidisers destroy organic vapour by combustion at 800 to 1000 degC. RTOs are used for paint-cure-oven VOC destruction at Lysaght and Stramit integrated post-form lines. Duct upstream of RTO is 316L stainless; duct downstream is hot-dip aluminised steel.

8. Local exhaust ventilation (LEV) — the workhorse of service centre compliance

Every dust, fume and mist source in a service centre gets its own LEV branch. Total LEV exhaust in a mid-sized Australian service centre is typically 50,000 to 250,000 m3/h, distributed across 20 to 80 individual branches. Each branch is sized for its source capture and transport velocity, with isolation dampers for maintenance. Branch sizing starts from capture velocity at the source, converts to volumetric flow at the hood face, then sizes the branch to maintain transport velocity. A typical slitter line knife-head coolant aerosol branch is 3,000 to 5,000 m3/h at 400 mm diameter (12 m/s transport). A plasma cutting bed downdraft table branch is 20,000 to 40,000 m3/h at 700 to 900 mm diameter (20 m/s). A laser cutting bed downdraft table branch is 15,000 to 30,000 m3/h at 600 to 800 mm. An abrasive blast cabinet branch is 8,000 to 15,000 m3/h at 500 mm (22 m/s). A powder-coat cure oven exhaust is 2,000 to 5,000 m3/h at 300 mm (12 m/s).

LEV systems are pressure-balanced — each branch sized so the static-pressure drop from hood face to main collection point is equal across all simultaneously-operating branches. Without balancing, branches closest to the fan starve more distant branches of capture velocity. Balancing dampers at each branch are used for commissioning trim; the fundamentals must be right at design stage. Make-up air sized for total exhaust at the design condition delivered through 316L stainless or hot-dip galvanised supply-air mains, with HEPA pre-filters at clean make-up zones and direct-gas-fired tempering for winter heating.

9. Typical project sizes — Australian service centre HVAC capital cost

A new Australian steel service centre HVAC project runs a predictable size range at 2026 prices:

• Small regional service centre (1 slitter + 1 CTL + 1 plasma cutter): Total LEV 30,000 to 70,000 m3/h, 8 to 18 hoods. Duct footprint AUD 250,000 to 500,000.
• Mid-size flat-product service centre (3 slitters + 2 CTLs + 1 laser + 1 plasma): Total LEV 80,000 to 150,000 m3/h, 25 to 45 hoods. Mixed galvanised and 316L. Duct footprint AUD 700,000 to 1.5 m.
• Mid-size stainless service centre (Atlas Steels Carlton VIC scale): Total LEV 60,000 to 120,000 m3/h, 25 to 40 hoods. Heavy 316L stainless content. Cr VI baghouse with HEPA polish. Duct footprint AUD 800,000 to 1.6 m.
• Mid-size aluminium service centre (Capral Penrith NSW scale): Total LEV 100,000 to 180,000 m3/h, 30 to 50 hoods. NFPA 484 combustible-metals zoning throughout. Bonded and grounded 316L mains. Wet-bath collection. Duct footprint AUD 1.2 m to 2.5 m.
• BlueScope Distribution flagship (Western Port VIC scale): Total LEV exceeds 250,000 m3/h across coated-coil slitter, CTL and packaging halls. Aluminised steel dominant. Duct footprint AUD 2.0 m to 4.0 m.
• InfraBuild Sydney flagship: Total LEV 150,000 to 250,000 m3/h across multiple slitter, CTL, plasma cutting, structural welding and warehouse zones. Conventional galvanised dominant with stainless on Cr VI zones. Duct footprint AUD 1.8 m to 3.5 m.
• Lysaght Coomera integrated roll-form plant: Total LEV 80,000 to 150,000 m3/h with integrated roll-form oil mist, in-line cutting fume, NFPA 86 powder-coat cure oven exhaust. Duct footprint AUD 1.0 m to 2.0 m.

10. The SBKJ machine configuration for Australian steel service centre HVAC fabrication

Service centre duct work spans the full range of fabrication demand — from heavy-gauge galvanised cutting fume mains to chemistry-resistant 316L stainless, from large-bore spiral swarf transport to fire-rated 2-hour penetrations, and from conventional rectangular AS 4254 duct to wear-lined construction for abrasive service. The right SBKJ machine configuration gives the fabricator the capability to serve every duct-material requirement in this guide from a Box Hill North VIC office floor.

10.1 SBAL-V stainless option auto duct line — the 316L workhorse

The SBAL-V auto duct production line is SBKJ’s flagship rectangular duct line and the right machine for 316L stainless service centre work. With the stainless-steel processing option, the SBAL-V handles 304 and 316L stainless sheet from 0.7 mm to 1.5 mm gauge in addition to standard galvanised, aluminised and painted carbon steel. The line includes stainless-rated decoiler with PE protective film handling, stainless-rated levelling rolls, dedicated TDF flange roll for stainless, and through-line surface protection. Production rate at 1.0 mm 316L is 4 to 6 m of finished duct per minute. For an Australian service centre fabricator serving BlueScope Distribution, InfraBuild, Atlas Steels, Capral Aluminium and Lysaght with 316L mains for Cr VI laser and plasma cutting fume, aluminium NFPA 484 dust mains, HF pickling exhaust, coolant aerosol collection, and clean make-up air, the SBAL-V is the right answer. The SBAL-V also handles the heavy-gauge 1.5 mm 316L specification for the most demanding HF and Cr VI mains.

10.2 SBAL-III auto duct line — heavy-gauge galvanised and aluminised

For heavy-gauge 1.6 to 2.0 mm galvanised, aluminised and painted carbon steel work, the SBAL-III auto duct line is the production solution. The SBAL-III handles sheet up to 2.0 mm with TDF flange forming, Pittsburgh lock or snap-lock seam forming, and full automation through coil entry, levelling, notching, shearing, brake-press forming and flange roll. Production rate at 1.6 mm is 8 to 12 m of finished duct per minute. The SBAL-III is the workhorse for general service centre exhaust mains — slitter swarf transport, CTL shear-drop, abrasive blast cabinet downstream, plasma and laser cutting fume mains downstream of the cutting bed, paint-spray-booth pre-separation, packaging and warehouse general ventilation.

10.3 SBSF-1525 stitchwelder — continuous longitudinal welded seam

The SBSF-1525 stitchwelder delivers continuous TIG welded seam on rectangular duct longitudinal lock. For chemical-fume-resistant duct (Cr VI, HF, aluminium NFPA 484, hot 250 degC fire-rated penetration) the seam must be welded continuously rather than relying on sealant alone. The SBSF-1525 lays down a continuous TIG bead at 600 to 900 mm/min travel speed in 1.2 mm 316L using argon shield gas at 12 L/min. The bead penetrates the lock-seam interlock and gives a hermetic continuous bond. Surface-finish the bead flush for service centres handling food-grade or medical-grade stainless downstream, or leave as-laid for industrial service. The SBSF-1525 also delivers continuous seam for fire-rated 250 degC/2-hour construction at galvanise kettle exhaust and powder-coat cure oven exhaust where the duct passes through fire-rated wall penetrations. The SBSF-1525 mounts inline with the SBAL-V or as a standalone bench welder for retrofit work.

10.4 SB-ZF1500 stitchwelder — longitudinal weld on spiral

The SB-ZF1500 longitudinal stitchwelder operates inline with the SBFB-1500 spiral tubeformer to deposit a continuous TIG bead along the formed spiral seam. The double-bond construction — spiral mechanical lock plus continuous TIG longitudinal weld — is the standard for HF-resistant pickling-line mains, Cr VI stainless laser and plasma cutting fume trunk mains, aluminium NFPA 484 dust trunk mains, and high-pressure baghouse-inlet duct at flagship service centres. The SB-ZF1500 handles 304 and 316L stainless up to 1.5 mm gauge at 800 mm/min travel speed. For spiral above 1000 mm diameter or for chemical-service spiral, the SB-ZF1500 is non-negotiable.

10.5 SBFB-1500 spiral tubeformer — swarf, coolant aerosol and cutting fume mains

Service centre dust, swarf and aerosol mains — slitter swarf conveying, CTL shear-drop dust, coolant aerosol mist mains, plasma and laser cutting fume mains downstream of the bed — are best fabricated as spiral round duct. Round duct gives the best aerodynamic profile for high transport velocity (18 to 22 m/s for solid dust, 10 to 13 m/s for aerosol mist) and the lowest abrasive-wear surface for swarf-laden streams. The SBFB-1500 spiral tubeformer produces round duct from 80 mm to 1500 mm diameter in galvanised, aluminised or stainless steel at 0.6 to 1.5 mm gauge. For service centre slitter-swarf service at 1.2 to 1.5 mm gauge in galvanised with optional internal Hardox or ceramic-tile lining at high-wear elbows, the SBFB-1500 is the practical production envelope. Production rate at 800 mm diameter, 1.2 mm gauge: 3 to 6 m/min.

10.6 SBPC1500 plasma cutter — transitions, hood apertures, manifolds

Service centre HVAC includes custom-geometry cut sheet plate — downdraft table apertures (plasma and laser cutting bed), slitter swarf hopper transitions, CTL flying-shear hood entries, abrasive blast cabinet manifold connections, and baghouse manifold transitions. The SBPC1500 plasma cutter handles 316L stainless up to 20 mm thickness and carbon steel up to 25 mm with HD plasma quality — clean kerf, minimal heat-affected zone, no slag. Cut transitions from CAD-generated cut files (use a Bystronic or Trumpf nest output where available), deburr with stainless wire wheel for stainless or carbon brush for carbon steel, and weld up the geometry with TIG or MIG. The SBPC1500 production rate is approximately 1.2 m/min on 1.5 mm 316L, dropping to 0.4 m/min on 10 mm carbon steel. For heavy-gauge 309 or 310S stainless at 200 to 450 degC galvanise kettle exhaust applications, the SBPC1500 handles the custom heavy-gauge cut work without the bottleneck of manual oxy-fuel cutting.

10.7 SBLR-600 lock former — Pittsburgh lock and snap lock

The SBLR-600 lock former produces Pittsburgh lock or snap-lock longitudinal seams on rectangular duct sections from the SBAL-V or SBAL-III. For 1.2 mm 316L stainless work, the SBLR-600 uses heavy-gauge tooling with reduced forming speed compared to galvanised. For 1.5 mm 316L Cr VI mains and aluminium NFPA 484 mains where the seam must subsequently be continuously TIG welded on the SBSF-1525, the SBLR-600 produces a tighter lock-seam profile for cleaner weld penetration.

10.8 SBTF-1500, SBTF-1602, SBTF-2020 spiral lines — large-bore trunk mains

For trunk mains above 1500 mm diameter — the largest service centre baghouse manifold duct, full-hall LEV trunk mains, multi-cabinet abrasive blast manifold — the SBTF series takes over from the SBFB-1500. SBTF-1500 produces up to 1500 mm; SBTF-1602 up to 1600 mm; SBTF-2020 up to 2000 mm diameter. Heavy gauge to 2.0 mm. All three machines accept the SB-ZF longitudinal stitchwelder for chemical-service continuous-weld construction. The SBTF-2020 is the largest spiral former in the SBKJ catalogue and is the right machine for any fabricator targeting BlueScope Distribution Western Port VIC or InfraBuild Sydney trunk-main contracts.

10.9 Fire-rated construction option — 250 degC/2-hour penetrations

The SBSF-1525 stitchwelder enables continuous TIG seam welding for fire-rated duct construction to AS 1530.4 250 degC/2-hour wall penetration. This is required for the duct passing through fire-rated walls between the slitter and CTL hall and the warehouse, between the powder-coat cure oven exhaust and the building roof, and at the galvanise kettle exhaust where present at integrated coater operations. Heavy-gauge 1.5 to 2.0 mm aluminised or 316L stainless with continuous welded seam and welded TDF flanges gives compliant fire-rated construction at the SBKJ production line output.

10.10 Heavy-gauge GAL ductwork for service centre exhaust — manual + SBSF-1525 + SBAL-III

For heavy-gauge 1.6 mm Z275 galvanised exhaust mains serving slitter swarf transport, CTL shear-drop dust, abrasive blast cabinet exhaust and general service centre dust mains, the production route is manual lock-form on the SBLR-600 for one-off heavy duct, plus the SBSF-1525 stitchwelder for continuous-seam construction where chemistry or fire-rating warrants, plus the SBAL-III auto duct line for series-volume work. Production rate on the SBAL-III at 1.6 mm Z275 is 8 to 12 m/min finished duct.

10.11 316L stainless 1.5 mm for Cr VI and HF mains — SBAL-V

For 316L stainless 1.5 mm gauge serving Cr VI stainless laser and plasma cutting fume mains, HF pickling exhaust where present, and aluminium NFPA 484 dust mains, the SBAL-V auto duct line with stainless option handles the full gauge range from 0.7 mm up to 1.5 mm in 316L with stainless-rated tooling and PE protective film throughout the forming train.

10.12 Heavy-gauge 309/310S stainless for galvanise kettle exhaust — manual + SBPC1500

For the heavy-gauge 200 to 450 degC galvanise kettle exhaust at integrated coater operations (BlueScope Port Kembla CGL5, CGL6, CGL7 lines), the duct material is 309 or 310S high-temperature stainless at 2.0 to 3.0 mm gauge. The production route is manual fabrication with the SBPC1500 plasma cutter for the custom-geometry cut work, plus TIG welding by qualified welder to AS/NZS 1554.6 specifications.

11. Practical fabrication and installation considerations

11.1 Bonding and grounding for NFPA 484 aluminium dust circuits

Every metre of duct in an aluminium dust circuit must be bonded and grounded to AS/NZS 60079 design guidance (less than 10 ohm continuous resistance to building earth). At fabrication time this means welded bonding tabs on every duct segment, copper or stainless-braid bonding straps across every TDF flange joint, and ground straps from the duct exterior to the building structural earth. For FRP duct (where used at wet-scrubber outlets), conductive carbon-fibre additive or external grounding tape is mandatory. The fabricator who omits bonding-tab welding at production time forces a site-weld retrofit that is slow, expensive and rarely as clean as the factory weld.

11.2 Thermal expansion

A 30 m run of galvanised carbon-steel duct expands approximately 90 mm between ambient and 300 degC service. 316L stainless expands approximately 75 mm over the same range. Service centre exhaust mains downstream of plasma and laser cutting (local temperature spike to 300 to 400 degC), powder-coat cure oven exhaust (continuous 200 degC), and galvanise kettle exhaust (continuous 450 degC) must include expansion joints — bellows in lower-temperature sections, brick-and-fibre in refractory-lined kettle exhaust — sized for design temperature range. Rigid mounting of long exhaust runs is a common cause of premature failure as thermal stress tears welded joints.

11.3 Inspection access

AS 4024 and AS 1885 both require regular inspection of service centre ductwork. Access ports sized for camera inspection (200 mm minimum) or personnel entry (600 mm) on confined-space-compliant work. Inspection-port positioning is process-driven: every 5 to 10 m on horizontal runs, at every elbow, at every branch take-off, on either side of every damper. Aluminium NFPA 484 dust mains additionally require quarterly inspection for dust accumulation, with any layer above 3 mm thickness triggering immediate cleaning.

11.4 Insulation and acoustic lagging

Service centre exhaust mains over manned work zones are insulated externally for personnel protection — exterior shell temperatures of 60 degC or higher are an AS 4024 burn hazard. Acoustic lagging on top of thermal insulation gives NC-65 acoustic compliance in production areas and NC-55 in adjacent warehouse zones. The combined insulation-and-lagging package is bulky and must be coordinated with structural-clearance budgets at design time — minimum 4.2 m clear height under duct for forklift movement.

11.5 Dampers and isolation

Every machine on a shared dust or fume main needs an isolation damper for safe maintenance. Dampers in service centre service are heavy-duty butterfly or guillotine designs with high-temperature seals, refractory packing where service temperature warrants, position indicators on the AS 4024 lock-out chain. Fire dampers per AS 1668.1 are required at zone boundaries; explosion-isolation valves per NFPA 660 are required between baghouse and inbound duct for combustible-aluminium-dust service. Plasma and laser cutting bed zone-isolation dampers along the bed length concentrate LEV airflow on the active cut zone.

11.6 LPG forklift Zone 2 separation

LPG-forklift charging and bottle-exchange areas trigger AS/NZS 60079 Zone 2 hazardous-area classification. Ductwork passing through Zone 2 areas requires Ex-rated supply-air fans, Ex-rated zone-area lighting, and avoidance of ductwork penetrations through Zone 2 boundary walls. Typical service-centre design includes a dedicated outdoor or roller-shutter-isolated forklift charging area separated from the cutting and slitting hall.

12. The 14-point checklist for a steel service centre HVAC specification

The condensed version of this entire guide is a 14-point checklist an engineer runs against any Australian service centre HVAC specification before sign-off:

1. Every cutting, slitting, forming, welding, blasting, painting and curing station mapped, classified by temperature and chemistry, and assigned to a dedicated LEV branch with documented capture velocity per ACGIH and AS 1668.2.
2. Carbon steel cutting fume and slitter swarf mains specified as Z275 hot-dip galvanised to AS 1397 at 1.2 to 1.6 mm gauge.
3. Cr VI stainless cutting fume mains specified as 316L stainless at 1.2 to 1.5 mm gauge with continuous welded longitudinal seam.
4. Aluminium NFPA 484 dust mains specified as 316L stainless or aluminised steel at 1.0 to 1.2 mm gauge, fully bonded and grounded to less than 10 ohm continuous resistance to building earth, terminating at wet-bath collector with hydrogen venting.
5. Coolant aerosol and oil mist mains specified as 316L stainless at 0.7 to 1.0 mm gauge, transport velocity 10 to 13 m/s, terminating at coalescer mist collector with electrostatic precipitator polish.
6. Plasma and laser cutting bed downdraft tables specified with zone-isolation dampers along the bed length, 1.5 to 2.0 m/s face velocity, dedicated baghouse with HEPA polish, continuous Cr VI emissions monitoring above 50 tonne monthly stainless throughput.
7. NFPA 484 separation rules enforced: aluminium dust circuit physically separated from carbon steel and stainless circuits with no shared mains, baghouse or cyclone.
8. Heat-treatment ovens (Bisalloy Q&T plate, powder-coat cure) specified per NFPA 86 with LEL monitoring, purge-and-light sequence, dedicated stack risers, fire-rated 250 degC/2-hour wall penetration construction.
9. Galvanise kettle exhaust at integrated coater operations (BlueScope Port Kembla CGL lines) specified as 309/310S high-temperature stainless at 2.0 to 3.0 mm gauge, refractory-lined where applicable.
10. LPG forklift Zone 2 hazardous-area separation enforced with Ex-rated electrical and dedicated charging area.
11. Make-up air system sized for total exhaust with neutral or slightly positive pressure on cutting and slitting floor relative to office, customer-counter showroom and QC lab; HEPA pre-filters in clean make-up zones.
12. Acoustic targets specified per AS/NZS 2107: NC-65 production, NC-55 warehouse, NC-50 customer counter, NC-45 office.
13. AS 4024 machinery-safety interface confirmed on every dust-extraction connection — interlocked guards, isolation dampers, inspection-port positioning.
14. SafeWork Australia and state EPA compliance evidence drafted before commissioning: workplace air sampling, stack-emission testing, continuous emissions monitoring at large sites.

Get an itemised SBKJ quote for service centre duct production →

13. ARBS 2026 and the SBKJ Australia connection

SBKJ Group exhibits at ARBS 2026 in Sydney (the Australian Refrigeration, Building Services and Air Conditioning Exhibition, the industry’s biennial HVAC&R trade show). The Australia Ducting Pty Ltd stand (exhibitor ID 236) shows the SBAL-V auto duct line with stainless option, SBAL-III heavy-gauge auto duct line, SBFB-1500 spiral tubeformer, SBSF-1525 stitchwelder and SBPC1500 plasma cutter. The stand team will walk fabricators through the steel-service-centre production envelope — how to fabricate 316L Cr VI laser cutting fume mains, aluminium NFPA 484 dust mains, slitter swarf spiral, CTL shear-drop dust mains, fire-rated 250 degC/2-hour penetrations — on-site at ARBS Sydney May 2026.

SBKJ Group operates from Box Hill North VIC (Melbourne) for the broader Australian steel service centre and metals distribution sector, with the Australia entity holding the AS/NZS 4254 documentation, ISO 9001 and ISO 14001 customer-supply experience, and direct technical engineering relationships with BlueScope Distribution, InfraBuild, Lysaght, Stramit, Atlas Steels, Australian Stainless Service Centre, Capral Aluminium, Orrcon Steel, Austube Mills, Bisalloy Steels and the broader Australian distribution market.

14. Industry bodies and reference resources

Australian steel service centre HVAC sits inside a broader industry network worth referencing in any specification document:

• Australian Steel Institute (ASI): Peak body for the Australian steel industry, covering steel-mill, distribution and fabrication sectors.
• Galvanizers Association of Australia (GAA): Technical body for hot-dip galvanising operations including coater HVAC.
• Steel Institute of Australia (SIA): Steel technical body referencing AS 1163, AS/NZS 3678 and AS/NZS 3679.
• Australian Steel Stockholders Network (ASSN): Trade body for steel distributors and service centres.
• Stainless Steel Association of Australia (SSAA): Technical body for stainless steel distribution and fabrication.
• Aluminium International Australia (AIA): Technical body for aluminium production and distribution.
• National Association of Aluminium (NAA): Aluminium industry body covering distribution and fabrication.
• ANZ Steel + Stainless + Aluminium Sector Council: Combined cross-sector council for the broader metals industry.
• SafeWork Australia: Workplace exposure standards and codes of practice for service centre hazards including Cr VI, AlOH3, ZnO, cutting fluid mist and oil mist.
• Standards Australia: AS 1668.2, AS 4254, AS 3957, AS/NZS 60079, AS 1397, AS 1163, AS 1450, AS 1444, AS 1554, AS/NZS 1554.1, AS/NZS 1554.6, AS/NZS 3678, AS/NZS 3679, AS 1665, AS/NZS 4453, AS 4036, AS 1318, AS 4801, AS 1668.1, AS 1851, AS 1530.4, AS/NZS 2107, AS/NZS 1158, AS/NZS 1428.1, AS 1742, AS 1657, AS 3580.

15. Where this connects to the rest of the SBKJ insight library

Steel service centre HVAC sits in the heavy-industry corner of the SBKJ insight library. Companion guides worth reading alongside:

• Foundry, iron, steel, aluminium, investment, lost foam & sand casting HVAC duct guide — the upstream foundry sector feeding bar and bloom into the distribution segment.
• Steel mill and smelter HVAC duct guide — primary steelmaking, BOF and EAF, continuous casting and rolling-mill exhaust. The upstream BlueScope Port Kembla, InfraBuild Sydney and Liberty Whyalla operation.
• Mining ventilation HVAC duct guide — upstream mining sector feeding iron ore and bauxite into the steel and aluminium supply chains.
• Welding methods for HVAC duct fabrication — the technique reference for the welded mains that dominate service centre Cr VI and NFPA 484 construction.
• Galvanised vs stainless steel duct — the material-selection reference behind the 316L vs Z275 galvanised decisions throughout this guide.
• Spiral duct forming guide — SBFB-1500 and SBTF-2020 production technique reference for service centre slitter swarf and cutting fume spiral mains.
• Cement plant HVAC duct guide — adjacent heavy-abrasive dust-loaded HVAC sector with shared wear-lined construction techniques.
• Australia HVAC duct fabrication setup 2026 — the practical machinery-and-factory-setup reference for an Australian service-centre-segment HVAC contractor.

FAQ

Why does fibre-laser and CNC plasma cutting fume need its own LEV branch in a steel service centre?

Fibre-laser cutting (Bystronic, Trumpf, Mazak, Mitsubishi, Amada at 6 kW and 12 kW) and CNC plasma cutting (Lincoln Electric, Hypertherm at 100 to 400 A) generate the most chemically aggressive fume in any steel service centre. Laser on carbon steel releases Fe2O3 (5 mg/m3 inhalable) and nano-particulate aerosol below 1 micron, plus O3 (0.1 ppm STEL) and NO2 (5 ppm STEL). Laser on stainless releases Cr VI (0.05 mg/m3 STEL, IARC Group 1) plus Ni (1 mg/m3). Laser on galvanised volatilises Zn to ZnO (5 mg/m3). Laser on aluminium releases AlOH3 (1 mg/m3) under NFPA 484 jurisdiction. Both technologies need dedicated LEV — 1.5 to 2.0 m/s face velocity at the bed slot, 18 to 22 m/s transport, downdraft tables with zone isolation, 316L stainless mains where Cr VI or HF is present, dedicated cartridge or pulse-jet baghouse, HEPA polish on the stack, and continuous Cr VI emissions monitoring above 50 tonne monthly stainless throughput.

Why is aluminium slitting and cutting dust treated as a deflagration hazard under NFPA 484?

Fine aluminium below 75 micron ignites at MIE below 50 mJ — a static discharge is enough. Kst runs 400 to 600 bar metre per second, Class ST3 (extremely severe). NFPA 484 (and consolidated NFPA 660) mandate wet-bath collection for fine aluminium dust below 500 micron, prohibit dry baghouses without engineered deflagration venting, require bonding and grounding of every metre of duct to less than 10 ohm, and prohibit mixing aluminium swarf with iron or steel swarf (thermite oxidiser risk). Aluminium dust circuits must be entirely separate from carbon-steel dust circuits, run in 316L stainless or aluminised steel duct with conductive bonding straps, terminate at wet collector under water flooding, and be subject to annual NFPA 484 dust hazard analysis. Hydrogen evolution at wet collector (Al + H2O = H2) is an additional hazard requiring collector-top venting.

How does Cr VI hexavalent chromium drive stainless service centre HVAC at Atlas Steels and ASSC?

Stainless slitting, cutting, grinding, polishing and welding all release Cr VI. SafeWork Australia reduced the Cr VI WES to 0.05 mg/m3 STEL in 2024 (IARC Group 1 carcinogen). Atlas Steels Carlton VIC (304, 316, 316L, 440, 13Cr, duplex 2205/2304, 317L, 904L, Inconel 625/718, Hastelloy C-276, Monel, Nitronic 50/60), Australian Stainless Service Centre (Sydney + Melbourne + Brisbane + Perth) and Suntech Steel all require LEV at every Cr VI source — slitter knife head, rotary shear, plasma cutting bed, laser cutting bed, grinding bench, polish wheel, MIG/TIG welding bay. Mains run in 316L stainless, terminate at dedicated Cr VI baghouse with HEPA polish, with continuous stack monitoring above 50 tonne monthly stainless throughput. Operator PAPR respirator is secondary control.

How do cutting fluid mist and coolant aerosol drive LEV at CNC plasma, laser, water jet and CTL lines?

Modern CNC plasma (Hypertherm 100 to 400 A), fibre laser (6 to 12 kW), water jet (60,000 psi/4,000 bar Flow, OMAX, Mistral, Bohle) and CTL lines (Bradbury Magna Tech, Coilmaster, Burghardt, TJK) use cutting fluids that aerosolise during cutting. Water-based emulsion (Castrol, Houghton, Quaker, Master Chemical, Fuchs), oil-based, semi-synthetic and synthetic coolants all generate aerosol at 5 mg/m3 STEL inhalable (oil mist separately at 5 mg/m3). LEV is dedicated mist collection at each cutting head — 0.3 to 0.5 m/s face velocity at coolant return tray, 316L stainless at 10 to 13 m/s transport to coalescer mist collector with electrostatic precipitator polish. Water jet adds silica RCS risk from garnet abrasive carrying contamination — the abrasive return tray needs its own dedicated extraction.

What HVAC envelope does a rotary slitter, cut-to-length line and precision flying shear need at a BlueScope Distribution or InfraBuild service centre?

Coil slitters (Quintette, Schuler, Bradbury, TBA at 25 to 2400 mm wide, 0.4 to 6.0 mm thick, 5 to 30 tonne coils) generate two LEV demands: coolant aerosol at the knife head (0.5 m/s capture, 10 to 13 m/s transport in 316L to coalescer) and slitting swarf at the swarf pit (0.5 to 1.0 m/s slot hood capture, 18 to 22 m/s in galvanised to baghouse). CTL lines (Bradbury Magna Tech with optical thickness gauge) add shear-drop dust at the flying shear (1.0 m/s capture, 18 to 22 m/s transport in galvanised to baghouse). A BlueScope Distribution Western Port VIC or Port Kembla NSW facility typically runs 3 to 6 slitters and 2 to 4 CTLs in parallel — total LEV 60,000 to 150,000 m3/h with separate aerosol and swarf circuits.

What SBKJ machine handles 316L stainless duct for Cr VI laser cutting fume and HF stainless pickling exhaust?

The SBAL-V stainless option auto duct line. Handles 304 and 316L stainless from 0.7 mm to 1.5 mm gauge in addition to galvanised and aluminised steel, with stainless-specific tooling, PE protective film through the forming train, and TDF flange on stainless. For a service centre fabricator serving BlueScope Distribution, InfraBuild, Atlas Steels, Australian Stainless Service Centre and Capral Aluminium, the SBAL-V at 1.5 mm 316L plus the SBSF-1525 stitchwelder for continuous longitudinal TIG weld gives a hermetic 316L duct for Cr VI laser cutting fume, HF pickling exhaust, aluminium NFPA 484 dust mains and cooling-water mains. Production rate at 1.0 mm 316L: 4 to 6 m of finished duct per minute.

What SBKJ machine handles heavy-gauge 1.6 mm galvanised duct for general service centre exhaust?

The SBAL-III auto duct line plus manual lock-form for one-off heavy duct plus SBSF-1525 stitchwelder for continuous-seam construction. The SBAL-III handles galvanised, aluminised and painted carbon steel up to 2.0 mm with TDF flange, Pittsburgh lock or snap lock, and full automation. Production rate 8 to 12 m of finished duct per minute on 1.6 mm Z275 to AS 1397. Pair with SBPC1500 plasma cutter for custom-geometry hood transitions, baghouse manifolds and downdraft-table apertures.

How does spiral round duct from the SBFB-1500 serve slitter swarf and coolant mist conveying?

Spiral round duct is the right geometry for any service centre dust or aerosol main above 200 mm diameter — best aerodynamic profile at 18 to 22 m/s solid dust transport and 10 to 13 m/s aerosol mist transport, lowest abrasive-wear surface. SBFB-1500 produces 80 mm to 1500 mm in galvanised, aluminised or stainless at 0.6 to 1.5 mm gauge. For trunk mains above 1500 mm at BlueScope Distribution and InfraBuild flagship sites, SBTF-1500, SBTF-1602 and SBTF-2020 cover up to 2000 mm. Production rate at 800 mm and 1.2 mm gauge: 3 to 6 m/min. With SB-ZF1500 longitudinal stitchwelder inline, the spiral can be continuously TIG welded for chemical-fume-resistant service.

What is the difference between an InfraBuild service centre, a BlueScope Distribution centre and an Atlas Steels stainless distributor from an HVAC perspective?

InfraBuild (formerly OneSteel, GFG Alliance Liberty, Sydney HQ, Whyalla SA EAF, biggest by tonnage) drives heaviest carbon steel slitting and CTL volume with conventional galvanised LEV at 18 to 22 m/s. BlueScope Distribution (Western Port VIC + Port Kembla NSW, Truecore + Colorbond + Galvalume + Zincalume) drives coated-coil specific HVAC with aluminised mains rather than galvanised to avoid zinc-fume cross-contamination. Atlas Steels Carlton VIC (biggest stainless and special-alloy, 304, 316, 316L, 440, 13Cr, duplex, Inconel, Hastelloy, Monel, titanium) drives the most demanding HVAC with Cr VI control, dedicated 316L mains throughout, separated tooling, and separate dust collection for stainless vs aluminium vs carbon steel under NFPA 484 separation. Each needs different SBKJ machine fitment.

How does a Lysaght or Stramit profile roll-former HVAC envelope differ from a flat-product service centre?

Profile roll-forming (Lysaght BlueScope Coomera + Sydney + Melbourne + Brisbane + Perth + Adelaide + Darwin; Stramit CSR; Bradbury, Samco, Tishken, JMP roll-formers) integrates flat coil through multi-station roll former producing roof sheet, wall sheet, structural section, SHS/RHS/CHS, precision tube. HVAC differs in three ways. First, roll-form oil mist at every station — 0.3 m/s capture, 316L or aluminised mist collection. Second, in-line cutting at line exit — flying shear, plasma or laser cut with same fume chemistry as flat product but with integrated line operation (cannot shut down one without the whole line). Third, post-cure paint and powder-coat oven at 200 degC under NFPA 86 with dedicated VOC and isocyanate exhaust to thermal oxidiser. Lysaght Coomera and several Stramit lines integrate post-form paint cure.

16. Contact SBKJ Group — Australian steel service centre HVAC machinery

SBKJ Group supplies HVAC duct production machinery to Australian fabricators serving the steel service centre and metals distribution sector. From Box Hill North VIC, we work with contractors fabricating exhaust ductwork for BlueScope Distribution (Western Port VIC + Port Kembla NSW), InfraBuild Wire and Distribution (Sydney HQ + Whyalla SA + Melbourne + Brisbane + Newcastle), Lysaght (Coomera + Sydney + Melbourne + Brisbane + Perth + Adelaide + Darwin), Stramit (CSR ASX:CSR), Apex Steel and Apex Engineered Solutions, NPS Stores, Coil Steels NSW, Northern Iron and Brass Brisbane, Atlas Steels (Carlton VIC), Australian Stainless Service Centre, Suntech Steel, Capral Aluminium (Penrith NSW + Bremer Park QLD + Smithfield SA + Welshpool WA), Orrcon Steel, Austube Mills (Sunshine VIC + Newcastle NSW + Welshpool WA), Bisalloy Steels (Unanderra NSW), InfraBuild Wire (Newcastle + Geelong), Tomago Aluminium and the broader Australian steel and metals distribution market.

• Email: sales@sbkjduct.com
• Phone: +61 435 074 994
• Web: sbkjduct.com
• Address: Box Hill North, VIC 3129, Australia
• ARBS 2026: Sydney, May 2026, exhibitor 236 — Australia Ducting Pty Ltd stand

For an itemised quote covering an SBAL-V stainless option line, SBAL-III heavy-gauge line, SBFB-1500 spiral tubeformer, SBSF-1525 stitchwelder, SB-ZF1500 longitudinal welder, SBPC1500 plasma cutter and SBLR-600 lock former — configured for a steel service centre HVAC fabricator in Australia — email sales@sbkjduct.com or call +61 435 074 994. An SBKJ mechanical engineer (not a salesperson) responds within 12 hours with itemised pricing, delivery, commissioning timeline and Australian-Standards documentation pack.

Get an itemised SBKJ quote for service centre duct production →